Next story in Space

Shrouded within protective plastic film, a technician works on repairs to the shuttle Discovery's fuel tank. Twenty-five years after the Challenger disaster, the fuel tank repairs serve as an illustration of NASA's heightened attention to potential safety issues.

If, as the cynic writes, “The only thing we learn from history is that we never learn from history” ... where does that leave the lessons of the Apollo 1, Challenger and Columbia space catastrophes?

NASA is observing a "Day of Remembrance" on Thursday to honor the astronauts lost during those three events, which all took place in late January and early February. But with the space shuttle program winding down, is there anything to be learned from that trio of tragedies?

In engineering terms, the three disasters taught lessons that space workers already knew but had forgotten — or at least had not thought to be important enough to sway operational choices. And all three disasters share a common root cause. That's the big reason why I resist calling these events "accidents": There was nothing random about them; rather, they were consequences of specific choices.

The
Apollo fire, on Jan. 27, 1967
, was made possible by a decision to believe that flammability in pressurized pure oxygen couldn’t be that bad, even if no tests had been run to check out that convenient assumption.

The
loss of Challenger, on Jan. 28, 1986
, was made possible by the decision that even though flexible O-ring seals had never been verified to function properly at sub-freezing temperatures, it was convenient to assume they would still do so in the absence of tests proving otherwise.

The
loss of Columbia, on Feb. 1, 2003,
was made possible by the decision — set down in writing — that even though observers suspected that tank debris might have hit the panel-covered leading edge of the shuttle's left wing, those panels were "probably" just as tough as other tile-covered areas that were previously hit. As was the case for the earlier tragedies, this was a claim that had never been tested.

Appallingly, in hindsight, when tests were made, they showed hazards that should never have been "assumed away." Pure oxygen fires were horrifically violent. Flexible pressure seals at low temperatures did not seat properly in their slots when hit by rocket thrust. And a leading-edge panel hit by a flying piece of insulation didn’t just get scratched — it shattered.

Bad choices
Of course, these three gross misjudgments weren’t the only times that space workers had made convenient assumptions. In other cases, the guesses turned out to be correct, or the feared scenario didn’t occur, or the mission was just lucky. But success at “dodging bullets” isn’t evidence that one is bulletproof, and such bad choices have a way of catching up with the chance-takers. Spaceflight is a particularly unforgiving environment for self-serving pretense and convenient assumptions, as these disasters (and others that fortunately didn’t involve the loss of life) keep reminding us.

The attitude toward safety that works, and that space workers knew all along was correct, is one of relentless verification of all assumptions. When in place, it makes spaceflight, in the words of former NASA Administrator Mike Griffin, "barely possible" at a minimum level of risk (but never at a totally safe level).

Two excruciating problems on recent shuttle missions testify to the current presence of this proper attitude in action. The shuttle Atlantis' launch in 2008
was delayed for weeks
by issues with a fuel tank quantity gauge. And NASA launch workers are currently dealing with a months-long delay for Discovery's final scheduled mission, due to problems with cracked spars on the fuel tank. Both problems were baffling and frustrating, but in both cases the shuttle team was committed to determining "root causes" rather than conveniently assuming that the missions could proceed. This took time, and testing, and patience — and it worked.

For the spars on Discovery, it turned out that an insidious conspiracy of a variation in one metal fabrication batch and of unusual assembly stresses led to the failures. Engineers determined those causes by reproducing the problems in laboratory tests. One shuttle had already launched with spars that probably had been cracked, but that had gone undetected — and fortunately, the spars still performed adequately. But a simple and cheap repair on all future spars from that batch has now been implemented.

Have lessons sunk in too late?
Now, the scary part is that the country at last has a human spaceflight operations team that fully “gets it” with regard to the only known approach that successfully minimizes risk ... and by the end of this year, that team will be dissolved. New teams, on new human space vehicle programs, will be pressing forward. These teams — at SpaceX, Boeing, United Launch Alliance, Orbital Sciences, Sierra Nevada and other spaceship companies — include veterans as well as workers who have had relatively little experience with NASA's culture of spaceflight.

They will undoubtedly be faced with the same attractive temptations of "convenient assumptions" as they encounter difficulties and puzzles in the development process. What are the chances that from the start they will consistently make the smart choices rather than the easy ones, considering how hard it was for the NASA team to come around?

How will they resist the temptation to rely exclusively on their intuitions, their judgments, their guesses, even in the absence of double-checking with Mother Nature? As the bumper sticker tells us, "Man forgives, God forgives, nature never" — to which must be added, “outer space never, ever."

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Here is where these current anniversary commemorations and recommitments take on far more than purely historical significance. A hideous price has been extracted. It has fallen heavily on those directly involved and on their families, to be sure, and also on all who strive to open the space frontier, and on the country’s future. But the payment of that price can go toward an awesome purchase, if future space workers know how to complete the transaction.

What's important for the next generation in spaceflight is not just knowledge — a cookbook of do’s and don’ts that must be followed by rote — but wisdom, which is the ability to make good choices.

The facts of safety are widely known, but it can be difficult to have cold, hard facts drive difficult decisions on spacecraft design, on operational concepts and ultimately spaceflight itself. We think we "know" some things about safety that in our hearts we don’t fully "believe" and act on. And after a disaster, we may realize that we did know better, but still made the wrong choices.

The memories of the men and women who died due to past misjudgments help us bridge the gap between "knowing" and ‘believing’ how to avoid poor choices. If that linkage between future choice-makers and past victims is missing, the list of casualties can only grow longer.

From joy to tragedy

The shuttle Challenger's mission in 1986 was meant to mark a milestone in spaceflight: the first orbital voyage of an American teacher. NASA's choice for the honor was Christa McAuliffe, a social-studies teacher at Concord High School in New Hampshire. Here, McAuliffe rides past the New Hampshire State House in Concord with her daughter Caroline and son Scott, during a Lions Club parade on July 21, 1985.
(Jim Cole / AP)
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Preparing Challenger

The space shuttle Challenger is transferred to the high bay of the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida on Dec. 17, 1985. Inside the cavernous VAB, the Challenger orbiter was mated with its solid rocket boosters and external tank in preparation for its launch a month later.
(Terry Renna / AP)
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Zero-G and she feels fine

Christa McAuliffe gets a preview of microgravity on NASA's specially equipped KC-135 "zero gravity" aircraft on Jan. 13, 1986. The plane flies in a parabolic pattern that provides short periods of weightlessness. For some people, those bouts of zero-G can induce nausea - which is why the airplane was nicknamed the "Vomit Comet."
(Science & Society Picture Library / Getty Images)
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To the launch pad

Practicing for an escape

Challenger's crew members practice the procedure for escaping from the launch pad at Kennedy Space Center using slide wire baskets. From left are Ronald McNair, Gregory Jarvis and Christa McAuliffe. Directly behind them are astronauts Judy Resnik and Ellison Onizuka. The basket system was designed to take the astronauts off the pad quickly if an emergency arose just before launch.
(NASA Headquarters)
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Heading for the pad

Challenger's crew members leave their quarters at Kennedy Space Center for the launch pad on Jan. 27, 1986. Commander Dick Scobee is at the front of the line, followed by Judy Resnick, Ronald McNair, Gregory Jarvis, Ellison Onizuka, Christa McAuliffe and pilot Michael Smith. NASA had to scrub the launch attempt on Jan. 27, due to high winds at the pad, and liftoff was rescheduled for Jan. 28.
(Steve Helber / AP)
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The first sign of trouble

A launch-pad camera captures a close-up view of the shuttle Challenger's liftoff on Jan. 28, 1986. From this camera position, a cloud of gray-brown smoke can be seen on the right side of the solid rocket booster, directly across from the letter "U" in "United States" on the orbiter. This was the first visible sign that a breach in the booster's joint may have occurred. Investigators determined that frigid overnight temperatures caused the booster joints' normally pliable rubber O-ring seals to become hard and non-flexible. The failure of the seals caused hot exhaust gases to blow through the joints, cutting into the external fuel tank.
(NASA Headquarters)
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Liftoff!

A wide-angle view shows the ascent of the shuttle Challenger on Jan. 28, 1986. In the seconds after ignition, the rocket engines' hot blast began the process of destruction.
(NASA Headquarters)
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Ice at the pad

Why did the O-rings fail? On the day of the shuttle Challenger's launch, icicles draped structures at NASA's Kennedy Space Center in Florida. The unusually cold weather, beyond the tolerances for which the rubber seals were approved, most likely caused the O-ring failure.
(NASA Headquarters)
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Watching the launch

Classmates of the son of America's first teacher-astronaut cheer as the space shuttle Challenger lifts skyward from Launch Pad 39B on Jan. 28, 1986. Their delight turned to horror as the shuttle exploded 73 seconds into flight. The boy in the white hat and glasses at center is Peter Billingsley, the star of "A Christmas Story" and a spokesman for the young astronaut program.
(Jim Cole / AP)
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The final seconds

The right solid rocket booster on the shuttle Challenger begins to explode, just a little more than a minute into the shuttle's ascent from NASA's Kennedy Space Center on Jan. 28, 1986.
(NASA via AFP-Getty Images)
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Moment of tragedy

Remains of the rockets

At about 76 seconds, fragments of the orbiter can be seen tumbling against a background of fire, smoke and vaporized propellants from Challenger's external fuel tank. The left solid rocket booster is still shooting skyward. A reddish-brown cloud envelops the disintegrating orbiter. The color is indicative of the nitrogen tetroxide oxidizer propellant in the orbiter's reaction control system.
(NASA Headquarters)
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Flying fragments

This picture, released by the presidential commission that investigated the Challenger tragedy, shows fragments of the orbiter flying away from the explosion on Jan. 28, 1986, 78 seconds after liftoff. The top arrow shows the orbiter's left wing. The center arrow shows the orbiter's main engine; and the bottom arrow shows the orbiter's forward fuselage. Investigators suggested that some of Challenger's crew members may have survived the explosion itself but died in the fall down to Earth.
(AP)
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The tragedy sinks in

Flight director Jay Greene studies data at his console inside Johnson Space Center's Mission Control Center in Texas, just minutes after the announcement that Challenger's ascent was not nominal.
(NASA)
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Death of a celebration

Carina Dolcino, senior class president at Concord High School, is stunned by the news that the space shuttle carrying Christa McAuliffe, one of the school's teachers, exploded after launch on Jan. 28, 1986. Students watched the launch on television sets scattered throughout the school in Concord, N.H., and a celebration had been planned for a successful liftoff.
(Ken Williams / Concord Monitor via AP)
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White House watch

President Ronald Reagan, center, is surrounded by members of his senior staff on Feb. 3, 1986, as he watches a TV replay of the Challenger shuttle explosion at the White House. From left are Larry Speakes, deputy White House press secretary; presidential assistant Dennis Thomas; special assistant Jim Kuhn; Reagan; White House communications director Patrick Buchanan; and chief of staff Donald Regan.
(Peter Souza / AP)
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Sympathy at school

Lisa Mitten of Concord, N.H., wipes tears from her eyes as her daughter Jessica reads some of the letters of sympathy that were on display at Concord High School on Feb. 1, 1986. Hundreds of Concord residents visited the school library to see the many telegrams and letters that were sent from all over the United States.
(Toby Talbot / AP)
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Recovering debris

A piece of Challenger

For weeks after the accident, search and recovery teams went out to retrieve Challenger debris from the Atlantic Ocean, with the help of the U.S. Coast Guard and U.S. Navy. Vessels brought pieces of debris to the Trident Basin at Cape Canaveral Air Force Station, from which they were shipped to Kennedy Space Center for investigation. The Coast Guard cutter Dallas transported this fragment of exterior tiling.
(NASA Headquarters)
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Retrieved from the ocean

A piece of debris from the space shuttle Challenger is hoisted onto the deck of the Stena Workhorse off the coast of Florida during a recovery mission.
(Time & Life Pictures via Getty Images)
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Farewell to the fallen

The remains of the shuttle Challenger's seven crew members are transferred from seven hearses to a MAC C-141 transport plane at the Kennedy Space Center's Shuttle Landing Facility, for transport to Dover Air Force Base, Del.
(NASA Headquarters)
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In memoriam

President Ronald Reagan and his wife, Nancy, stand with the wife of astronaut Michael Smith and other family members at a memorial service for the victims of the Challenger disaster.
(Diana Walker / Time & Life Pictures via Getty Image)
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Grim investigation

Apollo 11 moonwalker Neil Armstrong, a member of the presidential panel investigating the Challenger explosion, listens to testimony before the commission in Washington on Feb. 11, 1986. Another commission member, David Acheson, listens in the background. A model of the space shuttle sits on the table.
(Scott Stewart / AP)
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Solving the puzzle

Search and recovery teams located pieces of both the left and right sidewall of the shuttle Challenger during the months-long retrieval effort that followed the explosion on Jan. 28, 1986. Heat and fire damage scarred the right sidewall. But the left sidewall, depicted here, escaped the flames and suffered only from overload fractures and deep gouge marks. The largest intact piece formed part of the payload bay sidewall and measured approximately 30 by 12 feet.
(NASA Headquarters)
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Washed ashore

Some pieces of the shuttle Challenger did not surface until long after the explosion. A tractor carries one of the shuttle's elevons after it washed ashore on Cocoa Beach, Fla., on Dec. 17, 1996 ... almost 11 years after the loss of Challenger and its crew.
(AFP-Getty Images)
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Day of remembrance

Every January, NASA recalls the Challenger explosion as well as other space tragedies on a "Day of Remembrance." Here, NASA Administrator Sean O'Keefe lays a wreath at the Space Shuttle Challenger Memorial at Arlington National Cemetery in Virginia on Jan. 28, 2003. O'Keefe also paid tribute to the three astronauts of Apollo 1 who died in a launch pad fire on Jan. 27, 1967. Sadly, seven more astronauts died just days after this picture was taken, on Feb. 1, 2003, when the shuttle Columbia broke up during re-entry.
(Bill Ingalls / NASA via Getty Images)
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Editor's note:
This image contains graphic content that some viewers may find disturbing.

Video: 25 years after Challenger, teacher’s words still resonate

>>>as nasa prepares to retire its space shut hadal fleet this year this week marks a somber anniversary that reminds us while shuttle flights became come mop, they never became routine. it was 25 years ago this coming friday the shuttle "challenger" exploded over florida, killing all seven crew members, including a new
hampshire high school
teacher.
christa mcauliffe
had had hoped to take teaching to new heights but despite the tragedy, her mission continues today.

>>this was her last visit to our school.

>>christa mcauliffe
was the kind of teacher everyone wanted to v.

>>let's hear from it. wila's group back there.

>> reporter: and the kind of teach michaela pond aspires to be.

>>i was so sad i never got to take her class my senior year because would you walk by her classroom and you would see her jumping off desks and making thens come alive and could you hear her laugh.

>> reporter: now teaching in arlington, virginia, hahn was a student at
concord high school
in new hampshire when
christa mcauliffe
was chosen by nasa from among some 11,000 applicants to become the first
teacher in space
.

>>to hear that there's going to be a way to talk to a
teacher in space
, this was all new ideas and how does that happen?

>> reporter: mcauliffe
trained for a year with the crew of the "challenger" and prepared a series of lesson plans she would teach from orbit.

>>t minus ten.

>> reporter: her dream, to inspire students to literally
reach for the stars
.

>>we have main engine start.

>> reporter: mary liscomb studied teaching with
christa
. teaching is something that i think
christa
was born to do.

>>roger, "challenger."

>> reporter: but fate interveeped on a cold january morning.

>>"challenger," go at throttle up.

>> reporter: all seven crew members perished went "challenger" exploded 73 seconds after liftoff. of course,
christa mcauliffe
never got to teach those lessons from space but after all these years, she has reached more classrooms and more students than she likely ever imagined.

>>we acknowledge, we are standing by.

>> reporter: in
mcauliffe
's native massachusetts and some 50 other places, "challenger" learning centers are continuing the educational mission
mcauliffe
and her crewmates started. at the "challenger" center, students and often teachers embark on simulated
space missions
. the aim, to create excitement about math, science and space in schools and demonstrate the value of team work, the very things
mcauliffe
and the "challenger" crew had had hoped to accomplish.

>>see how her legacy through this is teaching children,cooperate, how to communicate, to love math and science. it makes
science and technology
relatable.

>>here is a teacher who took a risk. it didn't turn out the way she expected, but the
high hopes
she had for education impact all of them every day. they, too, can
reach for the stars
.

>> reporter: today there are dozens of schools around the world named after
christa mcauliffe
, but there are countless teachers who have turned her life's story into a teachable moment.

>>i always say there's nothing you can't do, you just have to try. and i try to talk in the way i know that
christa
inspired her students.

>>there's more on the legacy of
christa mcauliffe
and the challenger crew our website, nightly.msnbc.com.